In space-limited facilities where hydraulic and pneumatic tubes or pipes are present, it is difficult to tighten couplings using common open-ended wrenches. The prior art includes a number of devices which are gear-driven coupling devices that may be powered from a fixed point thereby avoiding the necessity of large arcuate swing areas that must be present for open-ended wrench turning. However, in the past such prior art devices have been integral with the coupling so that the tool cannot be removed. This presents three major drawbacks. The first is the expense involved in the necessary hardware for each coupling; the second and third disadvantages are the additional space and weight. The latter disadvantages are of particular importance in space vehicles where both weight and space are at a premium.